7x + 1 = 6x2


(v) 7x + 1 = 6x2
Sol. 7x + 1 = 6x2
∴ 0 = 6x2 – 7x – 1
∴ 6x2 – 7x – 1 = 0
Comparing with ax2 + bx + c = 0 we have a = 6, b = – 7, c = – 1
b2 – 4ac = (– 7)2 – 4 (6) (– 1)
= 49 + 24
= 73
By Formula method,
x
=
-  b ± √(b2 – 4ac)




2a







∴ x
=
-(-7) ± √73




2(6)







∴ x
=
7 ± √73




12







∴ x
=
7 + √73
or
7 - √73


12

12